Hesitation - relay click - TCS light

[Tokyo-Joe]

Hi guys,

I was hoping for a little info on what might be the issue my car is experiencing; more times then not when i get a minute or so down the road the TCS light will stay on and the car will hesitate - the electrics seem fine but it's almost like the fuel is cutting. When this happens what sounds clearly like a relay behind the passenger seat will click - click click click - judder judder judder. This could be one judder or a couple. This does not happen every time and seems to occur both when cold and when warm. Once it has happened once it won't happen again for the entire (sometimes long) journey. Turn it off and on and it's likely to do it again. The car revs cleanly and smoothly, pressures great. I had a compression test a few weeks ago with strong results.

I'm probably going to take it back to NW (for the love of god, my poor wallet..) but if I could be primed with any info before hand that would be great.

I have not checked the diag errors as I can't find my connection wire (it's not in the correct place) and I haven't had time to properly pull apart the dashboard to locate it.

I think it's worth mentioning that I had the original 20 yr old main relay in the car when I got it, I replaced it with a relay from a 97 car which has seemed perfect but I wonder if that one is also on it's way? Does a faulty main relay do this?

Thanks!
Joe

[NSXGB]

....I'd say it's about time to find 5 mins to have a look for the SCS connector....;)

[Tokyo-Joe]

Yeah I guess your right, I have a rolling road day next saturday, maybe i'll cancel that and make the time to properly find the connector. I had the carpet and lower glovebox off and couldn't find it when I last looked, it's either tucked into the center console area, up into the dash or has been removed!

[Kaz-kzukNA1]

Brave man using the used main relay without any services carried out….
In case other new owners were reading this thread, followings are something to be considered.


Please always replace your main relay with a new one and re-solder your existing one to be used as an emergency spare.

Several years ago, already the main relay on 2001/2002 models started to fail so by now, all NSX including the final production year 2005 models are not free from this issue and thus, no point in using the used one.


It’s a mechanical relay so even you re-solder it, you can’t do anything to the decay at the relay contact point.
It all depends on how many cycles the relay was operated so no one can predict its life span.


For DIY installation, please refer to the following link;
http://www.nsxcb.co.uk/showthread.php?6286-NSX-Health-Check-Service/page17&p=66800#post66800


Regarding the TCS warning light.
There has been several reports of clicking sound followed by TCS warning light when main relay started to play up while driving.
However, the most common symptom is the failure to fire up the engine. You can crank the engine but no fire up or managed to fire up but engine dies immediately or after a few miles.

Your issue seemed to be the same as others but could be multiple issues at the same time.

From your other post in the ‘Wanted’ section, you seemed to be sorting out the new relay so that will be a good starting point.

Hope you can fix everything in time for your event.

Kaz

[Tokyo-Joe]

Thanks Kaz, Simon has helped me out with a brand new main relay which I am hoping will fix the issue. Fingers crossed that is all it is :) I will update this thread but it does sound like a classic symptom.

[nobby]

hi

going to get someone to look at my old/spare main relay and re-do the solder.

is it obvious what points on the circuit board need to be redone etc?

is it obvious once opened up etc?

has anyone any pics of what to check/look for?

going to bring it in to one of our device services guy in my workplace ... without some background they might look at me blankly re my request!

[britlude]

when i serviced my main relay, the problem was on the main 'heavy duty' solder connections between the relay and the pcb. you may see some hairline cracks between the component pin and the solder. when i heated the solder the problem was obvious, the pin had corroded UNDER the solder joint, so while everything looked fine on top, with a nice solder fillet, the actual electrical joint was being broken by the corrosion on the pin itself. the solder was being pushed off of the pin!

it was an easy fix, the solder was removed, the pin cleaned of corrosion, and re-tinned. then the joint was resoldered. while the soldering iron was hot, the other joints were reflowed, just to check!

looks like it was the wrong choice of solder flux all those years ago!

[NSXGB]

looks like it was the wrong choice of solder flux all those years ago!

I think Kaz mentioned that the holes drilled in the PCB were manufactured slightly bigger than they should have been for the component legs....or something like that....

[Tokyo-Joe]

Right then, thanks all - new main relay in and 100% fixed the issue :)

I wish all car issues were as simple as swapping in a relay!

Cheers guys

[NSXGB]

Glad it fixed your issue.